Current output devices, as compared to voltage output devices, may provide superior neural recruitment characteristics during neural stimulation from an implantable medical device (IMD). However, the current output device requires a compliance voltage sufficient to drive stimulation current through a tissue/electrode interface. Because of variation in tissue/electrode interface impedance, the compliance voltage requirements can negatively impact battery longevity. Thus, there is a need for improved systems for providing stimulation current in implantable medical devices.